Blind-stitch machine



March 4, 1947.

c. w. MUELLER BLIND-STITCH MACHINE Filed July 29, 1943 4 Sheeis-Sheet 1 ail-E 7.

e/VEK March 4, 1947. c w E L 2,416,941

BLIND-STITCH MACHINE 4 Sheets-Sheet .2

Filed July 29 1945 l/flvroe (SH/4245s n4 MUELLER,

5y I 417-02 NE)! March 4, 1947. c. w. MUELLER' BLIND-STITCH MACHINE I 1 Filed July 29, 1945 4 Sheets sheef 5 Qt. r

lm/f/vroe: CHARLES W. MUELLER,

March 4, 1947.

c. w, MUELLER BLIND- STITCH MACHINE Filed July-29, 1945 4 sheets-sheet 4 lm/z/vroe 7 CHARLES M Mun/.64;

aw L

flrroA/EK Patented M... 4, 947

BLIND-STITCH MACHINE v Charles W. Mueller, St. Louis, Mo., assignor to Lewis Invisible Stitch Machine corporation of Maine Company, a

Application July 29, 1943, Serial No. 496,579

In certain types of blind-stitch sewing machines, -particularly the small high speed machines, it has been the common practice to have the-node-former carried by the work table. It is necessary that the node-former be yieldable in order to accommodate seams and also be so arranged that it may be withdrawn from the presser foot forthe insertion and removal ofwork. Heretofore, and prior to this invention, it was the common practice to make the entire work table yieldable. Thus, the node-former was mounted upon a yieldable work table as was also the work support-which consists of two independently moveable plattens. that support the work against the presser foot. a

Aheavy pressure or force is required to maintainlthe node-former'in position when forming a node through the opening in the presser'foot. This force is commonly exerted by a heavy spring which, in the construction mentioned, acts upon the work table. To open the machine for the insertion or removal of work, it is necessary for the operator, manually, and commonly through a knee press, to overcome the resistance of the heavy spring. Y

An object-of this invention 'is to provide a construction in which the machine may be opened without the necessity of overcomin the resistance of I the heavy yieldable force maintaining the node-former in operative position. Another object of-the invention is to provide a construction in which the work support may be moved away from the presser foot independently of the nodeformer. A further object of the invention is to provide a construction in which, by a single manual operation, the work support is moved away, from the presser foot and the node-former is positioned away from the presser foot, providing an ample unobstructedopening for the insertion orremoval of work. g

' The foregoing objects, and certain advantages that will hereinafter appear, are realized in the embodiment of the invention illustrated, by Way ofan example, in theaccompanying drawings and described in detailbelow: J

The drawings include: Fig. 1, which is a plan view of a. machine em bodying the, invention;

Fig, 2, which isa front elevation of the same; Fig. 3', which is a sectional front elevation of the same taken on the line 3-3 of. Fig. l;

1mg. 4, which is a'sectional plan taken on the line 4-4 of Fig. 2;:

-Figs. 5.6, T7, 8, 9, 10, a se s ctdeal ev ti ns- I d 11, which are trans taken -on the irregularlines 54, 66, 14, 8-4;, 9-4, |n |o, and

15 Claims. (Cl. 112176) l I 4 I, respectively of Fig. 3; and

Figs. 12 and 13, which show in elevation certain parts of the machine in two different positions of 7 their movement.

The machine illustrated in the drawings includes a frame upon which all of the mechanism is mounted. This frame comprises a base I, a post 2 secured to the base at the rear thereof, an arm 3 extending from the upper end of the post, a forwardly extending arm 4, secured to the end of the arm 3, and a work table 5 secured to the base at the front thereof and extending to the arm 4. The various sections of the frame are hollow, and within the sections, operatin and driving mechanism is mounted.

The sewing machine isdriven through a main shaft 6 that is journaled in the post 2 and the arm 3. This shaft extends through the post and has mounted thereon a combined pulley 1 and hand wheel 8. The belt 9 from a power not shown.

pulley is driven through a On the end of the arm 4, there is a presser foot- III which overhangs the end of the work table '5, The work is supported against thispresser The presser foot is of the usual and well-- foot. known construction and has an opening I I there-j through, through which, during the operation of the machine, nodes of material operated upon extend.

The stitch-forming mechanism is of the usual sewing machines of thisand well-known kind in type. A needle bar shaft I2 is journaled ,inthe arm 4 and extends through the end of the arm.

' On the extended end of the shaft l2, there is mounted a needle bar l3 which carries a curved needle [4. Through suitable connections with the main shaft, the needle bar shaft is oscillated to cause the needle to move across the opening in the presser foot. The particular machine illustrated is a chain-stitch machine and is provided with a looper l5 which cooperates with the needle in the formation of stitches. The invention, however, is not restricted to a chain-stitch,

blind-stitch machine as it is'equally applicable to a lock-stitch, blind-stitch machine of the same kind.

stitch line, is supported against the under side of the presser foot by a work support which consists of a pair of work-supporting plattens l6;and l1. These plattens are mounted for independent pivotal movement and for movement toward and away from the presser foot. They are shaft or an electric motor.

The work operated upon, in the region of the.

resiliently 'mountd on a shaft is formed a boss. I81). A

in the boss and extends therefro'mg A bracket}! l a. formed on the 'platten in the same manner. The mounting for the platten ll (Figs. and 11) includes a lever l8, in the nature of a bell crank lever, that is pivotally l9. One arm 18a of the lever is curved, as shown, and on the end thereof, there pivot pin 20, is mounted I! is pivotally mountedon the pivot pin 20. Another has secured thereto one end of a spring 2l. The other end of the spring 2| is securedin an adjustable anchor opening in the side wall of [the "work table .5. A check nut 23 secures the anchor "pin in adjusted position. The spring 2| is a comparatively light spring as the function of the plattens is merely to support the portion of the work operated upon against the presser foot.

, The end portionof the work table extending under the presser foot is of much greater disarm lBc of the lever I8 pin 22 threaded through an tance from the pres'ser foot than the work't'a-ble of the common machine of this kind. The distance between the work table and presser foot is sufficient, when unobstructed, to permit the ready insertion and removal of work between the p're'sser foot and the work table. "For the purpose of permitting the ready insertion and removal of I work, the plattens are retractable as the work lever 1-8 of the table is fixed. To h h ,7

lBtl. A-likelu pla't'ten ll is provided with a lug is "formed on the corresponding ten l-G which is indicated by and normally spaced from them, there is a rod 24 which extends from aluus'hing or'collar 25 that is secured "to a shaft Eli/(Fig.4). The rod 24 is normally spaced from theflu'gs tofpermi't limited independent movement of *the plattens. Upon rotating the shaft 25, counterclockwise ia'sseen in Figs. "10 and 11, theplatften supporting levers, such as the lever 18, are moved to withdraw the plattens to a position away from the p'resser foot- 1:0 the position of the platten 11, shown in Fig. '10.

Rotation of the shaft '26 to withdraw the plate tens is effected, manually, through a knee press 21(Figsf1 and29. I The knee press "is secured to an offset portion 281: of 'a rod 28 which-is seouredthrou'gh aconneotor 29 to a rod 30. This rod extends into I and it is j'ournaled therein. "Within'the base I (Figs. 4, 5, 6, '1'0,and *1'1) there is secured to the rod 50 a lever 3'1. To the en'd'of ithis lever, there is pivotally 'se'curedpne end of "a 'link'32, the other end of which is pivotally'se'cured to the end of a lever 33 that is secured on "the'sha'ft 26. 'When the knee press 21"('Figs. l and?) "is the base moved to the rightjthe rod'3ll -is'ro'tated counter:

clockwise. The lever 31 "(Figs."-4,,f5, and 6) draws the link down and rotates the shaft 2'5 to with-1 draw the 'pla'ttens to their open position, 'away' from the presser "foot. V

"The work-presenting mechanism 'for presenting "work to the needle incl-udes'jan oscillating node-former 55 6f the sector disk'type. Thej'node former (Fig. 4) is mounted on the end of a shaft 35 that is journaled in spaced bearings 36 and 3-l ofa Cradle-5 B. The 'cradle38is pivotally'mount ed on "centering pins 39' and 4'0 threaded through brackets ll and '42 extending inwardly from the side wallofthe'work'tab'le. The cradle 38 (Figs.

3 and D, and in consequence the node-former lever for the platthe numeral I 5. Underlying these 'lugs (Figs. '2', :4, 7, 1'0, and 11'),

is secured to a lug 44 extending from the cradle and the other end is secured to an adjustable anchorpin 45 threaded through an opening in the front wall of the work table. The force exerted on the cradle by the spring 43may be adjusted, to a limited extent, by adjusting the anchor pin 45. The anchor ,pin 45 is held in adjusted positi-on by a check nut 46.

The node-former is oscillated "in timed relation with the stitch-forming and feed mechanism. In the upper position, adjacent the presser foot (Fig. 8.), the node-former forces a node of the material operated upon through the opening in the presser foot and into the path of the needle.

node-former must yield-J It is, thus, yieldingly f mounted as above described.

The position of the node-former, in node-forming position, with respect to the 'pre'sser foot,determines the extent of the node formed and in consequence, the depth of penetration of the needle. In the machine illustrated, the depth of penetration of the needle "is adjustable through adjustment of the cradle 38, that is, by limiting the movement of the cradle under the action of the spring 43. For this purpose, the cradle is provided with a depending arm 4-1. At the'end countersunk of the arm 41 there is provided at opening 48, the countersink (Fig. 7) preferably being a sector of a "sphere. A'screw 49 having 9.

' head 55 complementary to the countersink ex-- tends through the opening and *the shank 5| thereof, which is of lesser diameter than the o ening, 'is threaded into the end of a rod "52. The other end of the rod has a hall-receiving fitting 53 secured thereon which receives a ball fitting 54 secured on a lever 55 'The lever '55 is secured on one end of a shaft '56 journaled in -a bearin bracket 51. On the other end of the shaft 55. there is secured another lever 51' which "is connected through .a link 58 to a movable block 59 slidab'ly mounted in the post 2. A threaded rod 60 having a knurled finger wheel 60 thereon en gages the block 59 and serves as the medium through which the depth of penetration ofx'the The nodeform'er is oscillated through .a train of actuating mechanism driven 'from the main" shaft and oscillatingthe "shaft '35. "This mechae ni'sm includesran excentric -5| '(Fig. 7.) mounted on the main shaft and an excentric strapffl surrounding the excentric. An excentri'c rod 33,

connected to the 'excentr'ic strap at one end, is-

pivotally connected, through 'a ball and socket joint, at the other end 'to the end or a "lever 6i.

The lever 64 extends from a "bushin'g irotatably mounted upon a shaftBB f'in theba'se "1.. Kn-

other lever 61 extends from 'theitbushing ".65 "and is connected through a ball and socket 'ioint to one end of a connecting rod. G'rne other endof the, connecting rod'oa is 'pivotally connected,

through'aball and "socket joint, -to one end of a lever 69. The lever 69 is' pivo'ted *between its ends on a pivot shaft 10 that 'is "formed integral with, and excentric with respect to, a shaft jl l' journaled in a transverse bearing bracketH in the b'ase l The other 'end o'f the' leve'r 59 pith lotally connected, through a balland socket'joint,

to a lever or crank arm 14 on theend of the shaft 35. On rotation of the main shaft, the excentricoscillates the levers 64 and 81 which, through the connecting rod 68, oscillates the lever 89. Oscillation of the lever 69 is transmitted through the link 13 and the crank arm 14 to the shaft 35. In Fig. 8, the connecting rod 68 is illustrated in one extreme position. In this position of the connecting rod, the node-former 34 is in node forming position. Fig. 9 illustrates the same parts in the opposite position. In this position, the node-former is withdrawn from the presser foot. The link 13, connecting the lever 69 and the crank arm 14, permits the shaft 35 to move, substantially vertically, when it is necessary for the node-former to yield.

From Figs. 8 and 9, it will be apparent that even with the work-supporting plattens withdrawn, the node-former would obstruct the open ing and the insertion and removal of work between the presser foot and the plattens. For this reason, in the machine illustrated, the nodeformer 34 is retracted, when the knee press 21 is actuated to the full extent, to a position (Fig. 10) in which there is a clear opening for the insertion and removal of work. Manual retraction or withdrawal of the nodeformer is effected by rotating the shaft "H and so shifting the pivot Iii. For this purpose, a spur gear 15 is secured on the shaft H. The gear 15 meshes with a gear 16 secured on a shaft 17 that is rotatably mounted in and extends through the bearing bracket 12. The gears 15 and 16 have a ratio of two to one. On the gear l6, and extending from the side thereof, there is a stud 18 which constitutes a crank. This stud I8 is positioned to be engaged by a shoe 79 secured on the link 32.

The normal position of the stud 18 (Fig. 6) is slightly above the horizontal plane passingv through the axis of the shaft 11. It is held in this position by a spring 80 (Figs. 4 and On the extended end of the shaft 11, there is secured a block 8| which carries an excentric pin 82 extending from the side thereof. One end of the I spring 80 is secured to this pin and the other end of the spring is secured to a stationary pin 83 extending inwardly from the end wall of the base I. v

The normal position of the shoe [9 (Fig. 6) is out of contact with and spaced above the stud 18. This relation permits a slight withdrawal of the work-supporting plattens l6 and H (Fig. 11) before the shoe engages the stud 18. The reason for this is to permit the operator to release the work while the machine is operating. The wide engagement of the plattens and presser foot with the work does not permit the work to be turned in the machines. Heretofore, in machines of this kind, when it was necessary to turn the work, the operator had to stop the machine, open it and then turn the work. By releasing the pres sure on the plattens, as above described, the work rides on the node-former and may be turned on the node-former as a pivot.

When the machine is stopped, and the operator presses the knee press the full extent, the shoe 19 engages the stud l8 and rotates the gear 16. The gear 15 and shaft H are thus rotated and the pivot pin is shifted. In Fig. 12, the pivot pin 10 and the node-former 34 are shown in their normal position. As the machine is stopped, the lower end of the lever 69 is held by the connectin; rod 68. Shifting of the pivot 10 thus causes movement of the lever about its pivotalconnec' tion with the connecting rod 68 and retracts the node-former 34 to the position illustrated in Figs. 10 and-13 Upon release of the knee press, the work-supporting plattens and the node-former return to their normal positions. This is effected through the springs acting on the plattens and the spring 80. v In the machine illustrated, the depth of penetration may be varied. This is effected through the excentric pivot. The shaft H extends through the bearing bracket 12 and has secured thereon a circular block 84. From this block, and through a slot provided therefor in the top of the work table, a finger lever extends. The edge of the block is provided with spaced detent recesses 86 and 81 which cooperate with a resilient detent 88 mounted in a disk sector 89 secured on the shaft 11. By shifting the finger lever from one position to the other, as repre sented'by the detent recesses 88 and 81, the excentric pivot 10 of the lever 69 is shifted. This changes the extent of oscillation of the nodeformer and so varies the penetration.

From the foregoing description .of the embodiment of the invention illustrated in the drawing, it will be seen that by this invention there is pro vided an easy opening machine and a machine in which the work may be readily turned while the machine is in operation. To maintain the node-v former in position to form a node, a spring force of approximately forty pounds is required. In prior machines, the operator, through the'knee press had to overcome this force to. open themachine. In the machine of this invention, the op-" erator need only over-balance a force of less than ten pounds to open the machine. By providing movement of the plattens priorto movement of the node-former, through the knee press, the operator uses the one control for turning the work and openingthe machine. v

- In machines of this kind, the adjustment of the node-former is very delicate. Where the nodeformer is carried by a'movable work table, the

'- machine must be adjusted frequently. This is because such machines are opened and-closed repeatedly in the course of a day. The closing is effectedby a complete release of the knee press which permits the work table to be slammed against the adjustable stop under the force of the heavy spring. In the machine of this, invention, the adjustment of the node-former is not disturbed in opening and closing the machine.

It will be obvious that various changesmay be made,by those skilled in the art, in the 'd'e tails of the embodiment of the invention illustrated in the drawings and described above, within the principles and scope of the invention as expressed in the appended claims.

I claim:

1. In a blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening therethrough, stitchforming mechanism on one side of the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including a movable node-former movable toward and away from the presser foot, mechanism for effecting movement of the node-former in timed relation with respect to the stitch-forming mechanism, a work support for supporting the work against the presser foot mounted for movement toward and away from the presser foot independently of the node-formeniand means for acting uponsaid mechanism for effecting movement ofthe node-"1 former awayfrom the presser foot, and means for moving the work-support away from the presser foot including means for actuating said means for efiecting movementoi the node-former away'fromthe pressure foot.

2; In a blind-stitch sewing machine ofthe kind described, the combination comprising a presser foot having an opening 'therethrough; stitchforming mechanism on one side of the presser foot, work-presentin mechanism for presenting work to the stitch-forming mechanism including a movable-node-former movable toward and away from the presser foot, mechan-i'sm for effecting movement of the node-former in timed relation with respect to the stitch-forming mechanism, a

work support for supporting the work against the presser foot mounted for movement toward and away from the presser foot independently of the-node-former, means for moving the work support away from thepresser foot, and means actuated thereby for acting upon said mechanism for efiecting movement of the node-former tomove the node-former'away from the presser foot.

3. In a blind-stitch sewing'machine of the kind 1 described; the combination comprising a presser foot having an opening therethrough, stitchforming mechanism on one side of the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including a movable node-former movable toward and away from the presser foot, mechanism for effecting movement of the node-former in timed relation with'respect to the stitch-forming mechanism, a

' work support for supporting thework against the presser foot mounted for movement toward and away from the presser foot independently of the node-former, means for moving the work support away from the presser foot, and; means operative upon movement of the work-support a predeter mined distance from the presser foot for actin upon said mechanism forefiecfiing movement. of the node-former to move the node-former away from the presser foot.

e. In a blindrstitchsewing machine of the kind described, the combination comprising a. presser foot having an' opening therethrou'gh, stitchforming mechanism on one: side of the presser foot,'work-presenting1mechanism for presenting work to the: stitch-forming mechanism: including a movablenode-former-movable toward and, away from; the presser foot, mechanism for effecting movement of the node-former in. timedv relation with respect to the stitch-forming mechanism including. an angularly movable shaft, a work support for supporting. the work against the,

presser foot mounted for movement toward and away'irom the presserfoot, and means for moving the work support away from the presser'footi including means for efiecting angular movementof the shaft of said mechanism about its axis for effecting movement of the node-former away from the presser foot.

5. In a, blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening ;therethrough, stitch-v forming mechanism on one side of the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including an angularly movable node-former, a work sup-i port for supporting the work against the presser foot mounted for movement toward and away from the presser foot, and means for moving the work supportvaway from the presser foot including means for. efiecting angular movement of the node-former. i

6:- In a 'blindi-stitch sewlngmachine of. the kind 7 described, the. combination. comprising stitchforming: mechanism including a movably" mo'unt-,

edlneedle bar and a needle carried :thereby, means-tor actuating said stitch-forming mechanism, work-presenting mechanism.Iincludingwamovable node-former movable toward and away from the path of the needle, actuating mecha nism forthe node-former, mechanism interconnesting the actuating means for thestich-forming mechanism and the node-former actuating mechanism positioning the node-former relative to the needle, and means for effecting actuation of the actuating mechanism independently of said interconnecting mechanism to :withdraw the" node-former away from the path- 0f the 8. In a blind-stitch sewing machine of the kind described, the combination comprisinga presser foot having anopening therethrough, stitchforrning mechanism on one side of the presser foot, work-presenting mechanism for present-' ing work to the stitch-forming mechanism :includ-ing a node-former movable between posi tions. adjacent to and away from the needle;

means for actuating the node-former in timed relation with respect to the needle, and man-u ally operative means for efiecting movement of the node-former independently of and in ac cordance with the movement effected by said node-former actuating means for moving the node former to a'position away from the needle.

9. In a blind-stitch sewing machine o-f-the kind described, the combination comprising a l V presser foothaving an opening therethrough,

stitch-forming mechanism on one sideof the presser foot, work-presenting mechanism "for presenting work to the stitch-forming mocha nism including a node-former movable toward and away from the presser foot, actuating me cha nism for the node-former including a rotatably v mounted shaft, and manually operative means for rotating the shaft about its axis to move the node-former away from the presserfoota 10. In a blind-stitch sewing machine of the kind described, the combination comprising a I presser foot having an opening therethrough;

stitch-forming mechanism onone side ofthe presser" foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including an oscillating node-former; 'oscill'atable between a position adjacent the presser foot and a position away-from the presser foot; means for oscillating the node former intimedrelation with respect to the stitch-forming-mecm 'ani'sm including an angularly movableshaft, and.

manually operable means fo'r effecting angular movement of the shaft independently of' said node-former oscillating means to position the node-former away from thepresserfoot.

11. In a blind-stitch sewing machine of thekind' described, the combination comprising a presser foot having an opening therethrough,-L

9 stitch-forming mechanism on one side of the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including an angularly movable node-former, means for efiecting movement of the nodeformer including a shaft, a lever for actuating the shaft and a shiftable pivot for the lever, and

manually operative means for shifting the pivot to position the node-former for the insertion and removal of work.

12. In a blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening therethrough, stitch-forming mechanism including a needle on one side of the presser foot, means for actuating the stitch-forming mechanism, work-presenting mechanism including an angularly movable nodeformer for presenting work to the needle, a resilient mounting for the node-former, means for actuating the node-former including a pivoted lever and a shiftable pivot for the lever, and manually operative means for shifting said shiftable pivot to position the node-former for the insertion removal of work.

13. In a blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening therethrough, stitch-forming mechanism including a needle on one side of the'presser foot, means for actuating the stitch-forming mechanism, work-presenting mechanism for presenting work to the stitchforming mechanism including a movable cradle, a shaft journaled in the cradle, resilient means for resiliently positioning the cradle and a nodeformer mounted on the shaft and positioned upon actuation to project a node of the work into the path of the needle, means for actuating one side of the presser foot, means for actuating the stitch-forming mechanism, a work support for supporting the work against the presser foot mounted for movement toward and away from the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including an oscillating node-former oscillatable between a position adjacent the presser foot and a position away from the presser foot, means for oscillating the node-former in timed relation with respect to the stitch-forming mechanism including an angularly movable shaft, and manually operable means for moving the work support away from the presser foot and effecting angular movement of the shaft about its axis to position the node-former for the removal and insertion of work.

15. In a blind-stitch sewing machine of the kind described, the combination comprising a presser foot having an opening therethrough, stitch-forming mechanism on one side of the presser foot, means for actuating the stitch-forming mechanism, a work support for supporting work against the presser foot mounted for movement toward and away from the presser foot, work-presenting mechanism for presenting work to the stitch-forming mechanism including an angularly movable node-former, means for effecting movement of the node-former including a shaft, a lever for actuating the shaft, and a shiftable pivot for the lever, and manually operative means for moving the work support away from the presser foot and for shifting said shiftable pivot to position the node-former for the insertion and removal of work.

CHARLES W. MUELLER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Gruman Apr. 30, 1940 

